[HELP] iPhone frozen. Cant open any apps.

My iPhone is frozen and I cannot open any apps on the springboard, not even the stock apps like Phone and SMS. Evrything was OK before I went to Installer and made a few changes:
1. Uninstalled WeTool-US (which was on the dock)
2. Installed WeTool (International Version)
3. Installed GNU Class Path
4. Installed JamVM
5. Tried installing Cydia (but main script execution failed) - (might not have caused the problem as its usual)

When I returned to springboeard, all icons were disappeared except WeTool-US on the dock which did not open.

Later I connected it to my PC using USB (as SSH did not work - connection closed be host), then I saw the root dir, it was like this: